Electric switch.



ATBNTED APR. 25, 1905.

No. 788,411-f W. D. R. MAODIARMID.

ELECTRIC SWITCH. APPLICATION FILED Inma, 1904.

2 SHEETS-SHEET 1.

No. 788,411. Y PATENTED APR. 25, 1905. W. D.'R. MAODIARMID.

ELECTRIC SWITCH.

UNITED STATES Patented April 25, 1905.

IENT OEEICE.

VESLEYy DUNCAN RICHARD MACDIARMID, OF OTTAWA, CANADA, AS-

SIGNOR OF FOUR-TENTHS TO EDWARD B. BATES, OF OTTAWA,

CANADA.

ELECTRIC SWITCH.

SPECIFICATION forming part of Letters Patent No. 788,411, dated April 25, 1905.

Application led January Z3, 1904. Serial No. 190,357.

T0 (all whom, it '1n/(ty concern,.-

Be it known that I, VVnsLnY DUNCAN RIGH- ARD MAGDIARMTD, machmist,of the city of Ottawa, in the county of Carleton, Province of Ontario, Canada, have invented certain new and useful Improvements in Electric Switches, of which the following is a specification.

My invention relates to improvements in electric switches of the type generally used for opening` and closing the circuit of electric lights, fans, and the like and in other places where comparatively low voltage is used; and the objects of my invention are to devise a switch for this class of work which may be used either in an incandescent-light socket, secured to a wall, or a cable or otherwise and which will require only a single pressure on the button to open the circuit and another single pressure on the same button to close the circuit, further objects being to make the device of simple and-cheap construction and such that it may be made with a minimum amount of manual labor; and it consists, essentially, of a rotatably-mounted commutator of conducting material, brushes adapted to be in contact with the surface thereof, the said comm utator having portions of its surface covered with insulating material, vertical and sloping grooves formed on the outer surface of the upper part of the rotatable portion, and a projection adapted to engage said grooves, said projection having a connection with the push-button,whereby when the push-button is depressed the projection engaging the groove will cause the commutator to rotate, the various parts of the device being constructed and arranged in detail as hereinafter more particularly described.

Figure 1 is a perspective View of one form of the switch with the cover removed therefrom. Fig. 2 is a sectional view of the same on the line X X, Fig. 4. Fig. 3 is a side View, the casing being shown in section. Fig. L is a plan view with the casing removed therefrom. Fig. 5 shows the construction of the switch and the arrangement thereof when adapted to be sunk in a wall with a iiush plate. Fig. isa diagrammatic View indicating the manner in which the switch could be used for turning on two lights successively and turning them olf together. Fig. 7 is a section through the commutator on the line Y Y, Fig. 2. Fig. 8 is a sectional elevation of an incandescent-lamp socket in which this switch is used. Fig. 9 is a side elevation of the same with the Vcover of the socket removed. Fig. 10 is a side elevation taken in a plane at right angles to Fig. 9. Fig. 11 is a sectional plan view on the line Z Z, Fig. 8. Fig. 12 is a sectional perspective view of the commutator and its grooves.

In the drawings like characters o f reference indicate corresponding parts in each figure.

In the drawings I have shown three principal forms which my invention may take: lirst, the switch adapted to be attached to a wall or other stationary support; secondly, the switch adapted to be sunk in a Wall or the like, so as to have its surface flush therewith, and, third, the construction of the switch when used in an incandescent-lamp socket. I will now describe the first ofthe above-mentioned constructions.

Referring particularly to Figs. 1, 2, 3, and 4:, A is the base, which may be of any desirable form and is constructed, preferably, of insulating material, such as wood, porcelain, or the like.

B B' are two uprights connected together at their lower extremities by an integral connecting-piece B2. A

C is a yoke consisting of the upper connecting-piece c and the downwardly-extending portions c c2. These downwardly-extending portions are provided with lateral guides c3 0*, adapted to engage the uprights B B.

Posts D D are screwed into the base or otherwise secured thereto and pass through the connecting-bar c of the yoke C, suitable heads being formed thereon. Spiral springs E E are provided on the posts D D, respectively, and tend to hold the depressible yoke up, so that it abuts the heads of the posts D D.

F is a rotatable commutator which is mounted upon a central pin Gr, which is screwed or otherwise secured to the base A. This commutator is provided alternately with conducting and non-conducting sections around the lower portion thereof, the conducting-sections being all integral with the main body of the commutator.

Brushes H H are secured to the connectingposts I I at their outer ends, and their inner ends are adapted to be in contact with the commutator-surface. The connecting-posts I I are preferably square in their horizontal cross-section and are sunk in correspondinglyshaped holes molded or formed in the base and secured to the base by screws M', passing therethrough. The connections are made in any suitable manner to their posts, such as by means of the extensions 2 3,-having holes therethrough for the wires and set-screws to claim the wires in position.

The upper portion of the commutator F is formed with a continuous groove extending around the same and comprising vertical portions f and inclined portions f all connected together.

rIhe cross-piece c is provided with a depending portion c5, in the lower portion of which a sliding bearing is formed for a pin J. A spring K presses against the end of this pin, thereby tending to force it inwardly. At the inner end of the pin a point j is formed and is adapted to extend into the groove in the commutator.

It may here be mentioned that the upper portion of each of the inclined grooves f is cut deeper into the metal than the upper portions of the vertical grooves f, and, similarly, the. lower portions of the vertical grooves f are cut deeper into the metal than the lower portions of the inclined grooves f.

It will now be seen that in the normal position of the switch, as shown in the drawings, the pin will extend into the upper portion of one of the inclined grooves. (See Fig. 12.) Consequently if the button L be depressed it will follow that the pin will travel down the inclined groove, thereby causing the commutator to rotate about its vertical axis. This will continue until the end of the pin enters the vertical groove. If the button is then released, the pin will slide up the vertical groove into the next inclined groove. The entire zigzag groove around the commutator is in the nature of a ratchet, the vertical grooves being deeper than the inclined ones at the bottom and the inclined ones being deeper than the vertical ones at the top, whereby shoulders are formed, and thus the pin is prevented from sliding back into the groove which it has just left. It will thus be seen that every time the button is pressed the commutator will rotate through an arc depending upon the pitch of the inclined grooves. Consequently if there are four inclined grooves and two diametrically opposite conducting segments or sections of the commutator and two diametrically opposite nonconducting sections one pressure of the button will establish a connection from one brush to another through the com mutator and the next pressure would break the connection.

The entire mechanism of the switch is entirely protected by means of the cap or covering M, through which the button extends.

Referring now to Fig. 5, the construction herein shown is that which would be adopted where the switch was to be sunk in the wall. The main features of this construction are similar to those above described. There is, however, aplate N, which is secured to the posts D D and also to the wall in which the switch is set.` A ange n is formed in the inner surface of the plate N and a rahbet a is formed on the base A. The protecting' covering or sheathing M extends between the flange n and the rabbet a.

In Fig. 6 I have indicated the connections diagrammatically which would be used on the commutator when the switch is intended to be used to turn on two lights consecutively by successive pressures on the button and to turn them both o` by the third pressure. The portion 2, which should be a third of the circumference of the commutator, is insulating material and the remainder is the unbroken surface of the commutator-body. 3 and 4f are the two lamps to be lighted. In the position shown the current is free to iiow through the two lamps. If the commutator were rotated through a third of the revolution in the direction indicatedA by the arrow, it will be seen that both lamps would be cut out. The next third of a revolution would relight the lamp 4 and the following third of a revolution would relight the lamp 3, and so on.

Referring now to the form of the switch adapted to be used with an incandescentlamp socket, as shown in Figs. 8, 9, 10, and 11, 5 is the outside casing of the socket, which may be of any suitable formand is preferably of the ordinary construction, consisting of a top piece or cap 6 and the body or lower portion 7, with an inside layer of insulating material 8. The method of attaching the lamp to the socket is immaterial; but I have shown one form consisting of the spring-grip 9 for the outside of the lamp and the spring contact-piece 10, adapted to contact with a central projection on the lamp. 11 and 12 are respectively top and bottom blocks of porcelain or any other suitable material connected together by the uprights 13 14 and secured thereto by screws. 15 is a commutator of substantially similar construction to the one shown in the previously-described constructions. This commutator has the sloping grooves 16 and the longitudinal grooves 17 formed in its surface in a manner exactly similar to the corresponding grooves described above. The conducting and non-conducting alternate sections or segments are also provided on this com- IOO IIO

mutatorat 18 and 19,1espectively. The commutator 15 is mounted upon a horizontal pin 20, which is held by the connecting-uprights 13 14. Instead of the yoke and the standards, as used in the other form of the device, I use in this forni a hollow pushbutton 21, which is adapted to extend through the outside casing of the socket and is formed with upper and lower guiding-slots 22 23, through which the standard 14 extends. 24 is a cylindrical block which is located within the hollow pushbutton 21 and straddles the upright 14. The pin or shaft 2O extends through the block 24 and holds it firmly against the upright 14. 25 is a spiral spring located between the block 14 and the end of the hollow push-button 21. A covering 26 of any suitable insulating. material, .such as gutta-percha or the like, is secured to the outside of the push-button to prevent its contacting electrically with the casing of the socket. 27 27 are washers located between the ends ofthe commutator and the uprights 13 14 to hold the commutator in its proper position on the shaft longitudinally. In the extension 28 of the hollow push-button a bearing 29 is formed, and a pin 30 extends therethrough and into the grooves in the commutator. A spring 31 tends to continually force the pin 30 inwardly. The wires of the cable come through the upper opening of the socket and are secured, respectively, to the binding-screws 32 33, the former of which is electrically connected with the central contact-springs 1() and the latter of which is connected by the bracket 34 to the contactbrush 35, which is in contact with the surface of the commutator.

The body of the commutator or, in other words, the conducting-segments thereof are connected with the outside spring-grip 9 through the shaft or pin 20, the uprights 13 and 14, the screws 36 36, and the iiange 37. It will thus be seen that when the push-button is forced inwardly the commutator will be rotated, and the result. will be that if the brush 35 contacts with a non-conducting segment the light will be cut off, but as soon as it contacts with the conducting-segment the current will be free to flow and the light will be lighted.

1t will now be seen that I have devised an extremely useful form of switch, which may be adapted to a great variety of uses. It is further to be noted that the construction of the switch is simple and cheap, as almost all the parts may be stamped out without requiring a large amount of manual labor.

The advantage of the push-button on a lampsocket is one of the most important features of the invention, as instead of requiring a twisting motion, as is usual in most switches used in lamp-sockets at the present time, a pinching motion is all that is required, the thumb resting on the socket and the finger on the push-button. It is therefore a simple matter to open the circuit with one hand, whereas with the turning switches if the lamp is hanging loosely on a cable it is generally necessary to hold it with one hand and turn the switch with the other.

It is to be understood that I do not wish to limit myself to the exact details of construction herein shown and described, as there are a number of variations in detail which might be made without departing from the spirit of my invention.

What I claim as my invention is- 1. In a device of the class described the combination with a rotatable commutator having the body thereof formed with a plurality of conducting and non-conducting segments arranged alternately around a portion of its length and a brush contacting with the surface of said commutator, a portion of the commutator being also formed with longitudinal and inclined grooves connected together, a projection extending into said groove, a carrier having a sliding bearing for said projection, a spring secured to said carrier and engaging the end of the pin, spring means tending to hold the projection toward one end of the commutator and means for forcing the same toward the other end of the commutator whereby the commutator is rotated as and for the purpose specified.

2. The combination with the commutator and a spindle or shaft upon which the same is rotatably mounted, said commutator having a portion of its surface formed with conducting and non-conducting segments arranged alternately around the same, and an adjacent portion formed with longitudinal and inclined grooves connected together, of a brush adapted to contact with the surface of thesegments, a hollow push-button slidably mounted on the end of said spindle, a pin slidably held in a bearing carried by said hollow push-button, a spring adapted to engage the end of said pin and force the same inwardly, 4a spiral spring located in said hollow push-button between the outer end thereof and the outer extremity of the spindle as and for the purpose specified.

3. In a device of the class described the combination with the commutator and the shaft upon which the same is rotatably mounted, said commutator having conducting and nonconducting segments arranged alternately around the surface of a portion thereof, of. a brush contacting with the surface of said seg'- Inents, the adjacent portion of the surface of said commutator having longitudinal and inclined grooves therein connected together, a pin spring held in engagement with said groove, a pair of electrical conductors, means for connecting'one of said conductors directly with one terminal of a lamp or the like, means for connecting the other conductor through the brush and commutator with the other terminal of the lamp or thel like when the brush is in contact with one of the conducting-seg- IIO ments and means for moving the pin in a direction parallel with the axis oi' the commutator whereby the com mutator is rotated as and for the purpose specified.

4. In adevice of the class described the combination with a commutator having conducting and non-conducting peripheral sections and coacting contacts connected to the circuit- Wires, of longitudinal and inclined grooves arranged around a portion of the surface of the commutator and connected together, the inner portions of the inclined grooves and the outer portions of thelongitudinal grooves being deeper than the inner portions of the longitudinal grooves and the outer portions of WESLEY DUNCAN RICHARD MAGDIARMID.

llitnesses:

EDWARD P. Fn'ri-IERs'rovHAUGH,y EDWARD B. SHEFFIELD. 

